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This document explores the fundamental differences between viruses and bacteria, highlighting their structural and functional distinctions. It also delves into how antiviral drugs function to combat viral infections, discussing common cases such as influenza and HIV/AIDS. The document explains that viruses are submicroscopic entities that cannot reproduce independently, whereas bacteria can replicate on their own. Additionally, it addresses the challenges faced in tackling diseases like AIDS, emphasizing the mutating nature of HIV and the effectiveness of drugs like AZT in managing the condition.
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D.7.1 • State how viruses differ from bacteria.
List the differences you know of between bacteria and viruses. Viruses Bacteria
List the differences you know of between bacteria and viruses. Viruses • Submicroscopic • Has either a section of DNA or RNA surrounded by a coat of packed protein units called capsomeres. • No cell wall • Can’t reproduce without a living host. Takes over cell’s machinery to produce more viruses. Bacteria • Microscopic • Has single, circular strand of DNA—is able to manufacture RNA from the DNA. • Cell wall • Can reproduce on its own.
D.7.2 • Describe the different ways in which antiviral drugs work.
Describe the different ways in which antiviral drugs work. Well known viral infections • Common cold • Influenza (Including H1N1) • HIV/AIDS • Chicken Pox • Herpes/warts What is the body’s natural defense to viral infections?
Describe the different ways in which antiviral drugs work. • Viruses multiply very quickly, so antiviral drugs will often have little effect by the time symptoms appear. • Goal of antiviral drugs is to stop replication.
Describe the different ways in which antiviral drugs work. • Acyclovir is used as a cream or orally to fight herpes viruses. • Shortens the time of the outbreak, but does not prevent recurrences. • It stops replication of viral DNA, and prevents virus from multiplying.
Describe the different ways in which antiviral drugs work. • Other antiviral drugs prevent new viruses from leaving the cell. • Amantadine (C10H17N) is used to treat influenza. It inhibits the active site of an enzyme which helps the virus to stick to the cell wall.
D.7.3 • Discuss the difficulties associated with solving the AIDS problem.
Discuss the difficulties associated with solving the AIDS problem. • HIV (Human Immunodeficiency Virus) can lead to AIDS (Acquired Immune Deficiency Syndrome). • HIV attacks white blood cells called T helper cells (T4-cells). • HIV therefore destroys the body’s ability to fight infections, leading to common infections (pneumonia, influenza) which can become life threatening (AIDS).
Discuss the difficulties associated with solving the AIDS problem. • The virus is a retrovirus since is contains RNA instead of DNA. • It makes viral DNA from RNA using an enzyme called reverse transcriptase. • One of the problems with antiviral drugs for HIV is the virus is constantly mutating. • A drug called AZT has been used to inhibit the reverse transcriptase, and this does not affect normal cells. • AZT has been effective in prolonging the period until AIDS develops.